Vinyl chloride resins have been conventionally widely used for side protection moles of automobiles. The vinyl chloride resins are very suitable for such uses because they are excellent in scratch resistance and available at a low price. However, the vinyl chloride resins generate harmful gas when burned, and hence there is involved a problem of environmental pollution.
By the way, olefin thermoplastic elastomers are used widely for automobile parts, industrial machine parts, electric and electronic parts, building materials, etc. as elastomers suitable for saving energy or saving natural resource type, particularly as replacements for vulcanized rubbers, because they are lightweight and can be easily recycled.
Further, from the viewpoint of the protection of earth environment, the vinyl chloride resins which generate harmful gas when burned have been recently replaced with the olefin thermoplastic elastomers which generate no harmful gas.
However, the molded articles produced from the conventional olefin thermoplastic elastomers are inferior in scratch resistance to the molded articles produced from the vinyl chloride resins, and therefore, an improvement of the scratch resistance has been eagerly desired for the olefin thermoplastic elastomers.
Under such circumstances as mentioned above, the present inventors have earnestly studied on the olefin thermoplastic elastomers having high scratch resistance and molded articles thereof. As a result, they have found the followings and accomplished the present invention.
(1) When a crystalline polyolefin resin, a specific block copolymer and an olefin rubber are blended in a specific ratio, there can be obtained an olefin thermoplastic elastomer capable of providing a molded article of high scratch resistance.
(2) When a partially or perfectly crosslinked thermoplastic elastomer which comprises a crystalline polyolefin resin and an olefin rubber, and a specific block copolymer are blended in a specific ratio, there can be obtained an olefin thermoplastic elastomer capable of providing a molded article of high scratch resistance.
(3) When a crystalline polyolefin resin (or a thermoplastic elastomer), a specific block copolymer, and any one of silicone oil, an ester of aliphatic alcohol and a dicarboxylic acid or a fatty acid and a fluorine polymer are blended in a specific ratio, there can be obtained an olefin thermoplastic elastomer capable of providing a molded article of high scratch resistance.
(4) When a laminate comprising a substrate which is formed from a partially or perfectly crosslinked thermoplastic elastomer comprising a crystalline polyolefin resin and an olefin rubber and a skin layer which is formed from a thermoplastic elastomer comprising a crystalline polyolefin resin and a specific block copolymer in a specific ratio is prepared, there can be obtained a thermoplastic elastomer laminate of high scratch resistance and high heat resistance which is lightweight, can be easily recycled and generate no harmful gas when burned.
(5) When a laminate comprising a substrate which is formed from a crystalline polyolefin resin and a skin layer which is formed from a thermoplastic elastomer comprising a crystalline polyolefin resin and a specific block copolymer in a specific ratio is prepared, there can be obtained a thermoplastic elastomer laminate of high scratch resistance and high heat resistance which is lightweight, can be easily recycled and generate no harmful gas when burned.